6561881502 has 32 divisors (see below), whose sum is σ = 14322680064. Its totient is φ = 1987636800.

The previous prime is 6561881497. The next prime is 6561881503. The reversal of 6561881502 is 2051881656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561881503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 153727 + ... + 191717.

It is an arithmetic number, because the mean of its divisors is an integer number (447583752).

Almost surely, 2^6561881502 is an apocalyptic number.

6561881502 is an abundant number, since it is smaller than the sum of its proper divisors (7760798562).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561881502 is a wasteful number, since it uses less digits than its factorization.

6561881502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40624.

The product of its (nonzero) digits is 115200, while the sum is 42.

The square root of 6561881502 is about 81005.4411876141. The cubic root of 6561881502 is about 1872.1592777809.

The spelling of 6561881502 in words is "six billion, five hundred sixty-one million, eight hundred eighty-one thousand, five hundred two".